This invention relates to a transfer machining system capable of conveying workpieces at a single pitch.
There are cases where a conventional transfer machining system must be equipped with a manufacturing line which includes a mixture of machine tools such as milling machines having a large working area necessary for machining work, and machine tools such as drilling machines having a small working area. The state of the art is such that the various machine tools must be spaced apart at intervals that depend upon the respective working areas.
An example of a prior-art arrangement for conveying workpieces in a manufacturing line of this kind is disclosed in Japanese Utility Model Application Laid-Open (KOKAI) No. 59-39153. The disclosed art includes a plurality of conveyor devices having juxtaposed conveyor bars and is so adapted that the driven conveyor bars are selectively changed whenever necessary. In this manner the pitch at which the workpieces are conveyed can be changed. Owing to such a configuration, however, the conveyor devices are extremely complex and involve complicated control operations. In addition, controlling the operation timing of the machines is a troublesome task.